Imatinib, chemically 4-[(4-methyl-1-piperazinyl)methyl]-N-[4-methyl-3-[[4-(3 -pyridinyl)-2-pyrimidinyl]amino]phenyl]benzamide, is represented by the following structure:

Imatinib and its salts are anti-tumor agents, which were disclosed in U.S. Pat. No. 5,521,184. Two crystalline modifications (α-form and β-form) of imatinib mesylate were mentioned in WO 99/03854.
WO 99/03854 mentioned amorphous imatinib mesylate, but it did not make any reference to hydrate of imatinib mesylate.
We have discovered a stable novel crystalline form of imatinib mesylate. The novel form is at least as stable as the reported forms, α- and β-forms. The novel crystalline form is stable over the time and has good flow properties and so, the novel crystalline form is suitable for formulating imatinib mesylate.
Amorphous forms of pharmaceutical products are usually known to have better dissolution properties than their crystalline forms. If amorphous form of a pharmaceutical product is stable enough, it can be formulated to a pharmaceutical composition having good dissolution properties.
We have discovered hydrate of imatinib mesylate.
We have also discovered a sufficiently stable non-hygroscopic amorphous form of imatinib mesylate hydrate. So, amorphous form of imatinib mesylate hydrate can be utilized to prepare stable pharmaceutical dosage forms having good dissolution properties.
One object of the present invention is to provide a stable novel crystalline form of imatinib mesylate, hydrate of imatinib mesylate and amorphous imatinib mesylate hydrate.
Another object of the present invention is to provide processes for preparing the novel crystalline form of imatinib mesylate, hydrate of imatinib mesylate and amorphous imatinib mesylate hydrate.
Still another object of the present invention is to provide pharmaceutical compositions containing the novel crystalline form of imatinib mesylate, hydrate of imatinib mesylate and amorphous imatinib mesylate hydrate.